Chemistry - Study Mode

[#526] A non-electronic conductor is
Correct Answer

(D) None of these

Explanation

Solution: Either the wording of the question is wrong or it doesn’t have a correct option. A non-conductor is a substance which does not allow the passage of electricity. As a general rule, all metals (Iron, Mercury, etc) are good conductors. Nonmetals are non-conductors, except for carbon in the form of graphite and the gas carbon. Copper Sulphate is a good electrolyte (a liquid which allows the passage of electricity). So all the options given in the question are good electrical conductors.

[#527] The anode of a dry cell is made up of
Correct Answer

(C) Zinc

Explanation

Solution: A standard dry cell comprises a zinc anode, usually in the form of a cylindrical pot, with a carbon cathode in the form of a central rod. The electrolyte is ammonium chloride in the form of a paste next to the zinc anode.

[#528] The coating of a thin layer of zinc on steel or iron objects is known as
Correct Answer

(C) Galvanising

Explanation

Solution: Galvanisation is a process of protecting iron or steel from rusting by coating them with a thin layer of zinc.

[#529] Normal rainwater is slightly acidic due to the presence of
Correct Answer

(A) Carbon dioxide

Explanation

Solution: The acidity of rainwater comes from the natural presence of three substances (CO 2 , NO, and SO 2 ) found in the troposphere (the lowest layer of the atmosphere). As is seen in Table I, carbon dioxide (CO 2 ) is present in the greatest concentration and therefore contributes the most to the natural acidity of rainwater.

[#530] Global warming is mainly due to accumulation of
Correct Answer

(C) Carbon dioxide

Explanation

Solution: Global Warming refers to average increase in the earth’s temperature due to increase in pollution which results in greenhouse effect which in turn leads to climate change. Global warming may lead to rise in the sea level due to melting of glaciers, shrinkage of forests, changes in the rainfall pattern and wide range of impacts on plants and humans. The greenhouse gases such as carbon dioxide accumulate into the atmosphere and trap heat that would normally exit into the outer space.